make a copy of the document (backup)
try switching to another output style –
try unformating and reformating (convert to unformatted NOT TO PLAIN TEXT
Perhaps the document has a corruption, and if so, you should run thru the document cleanup steps.
https://support.clarivate.com/Endnote/s/article/EndNote-Citations-Shifted-Up-in-the-Document?language=en_US